In recent years, leakage of confidential information through computers used in a company has become a problem. For example, a case may be considered where an employee takes a note-type personal computer provided with a hard disk drive storing his or her company's confidential data out of the office and he or she carelessly leaves the computer in a given place outside the office. In this case, there is a possibility that the company's confidential data may be leaked through his or her computer. Another case may be considered where a malicious employee copies his or her company's confidential data from a file server or a hard disk drive of a computer provided in the office to a USB (universal serial bus) memory or a CD-R (compact disc-recordable) so as to intentionally leak the data to a third-party.
In order to prevent such leakage of company's confidential information through a computer, the present inventor has proposed a thin client system. For example, a network booting thin client system, a screen transfer type thin client system, and a virtual PC type thin client system can be taken as the thin client system provided by the present applicant (refer to, e.g., NPLs (Non Patent Literatures) 1 to 3).